“State and Industry Petitioners assert that EPA improperly ‘delegated’ its judgment to the IPCC, USGCRP, and NRC by relying on these assessments of climate-change science. See U.S. Telecom Ass’n v. FCC, 359 F.3d 554, 566 (D.C. Cir. 2004). This argument is little more than a semantic trick. EPA did not delegate, explicitly or otherwise, any decision-making to any of those entities. EPA simply did here what it and other decisionmakers often must do to make a science-based judgment: it sought out and reviewed existing scientific evidence to determine whether a particular finding was warranted. It makes no difference that much of the scientific evidence in large part consisted of ‘syntheses’ of individual studies and research. Even individual studies and research papers often synthesize past work in an area and then build upon it. This is how science works. EPA is not required to re-prove the existence of the atom every time it approaches a scientific question” (emphasis mine, but it kinda sounds like the judges were leaning into it, eh?)